In view of the increasing importance of Internet services and the increasing demand for high-speed access to Internet data, the use of a DTH (Direct To Home) satellite broadcasting system might be advantageous to enable Internet access to a plurality of users. Indeed, a DVB (Digital Video Broadcast) satellite may deliver data at very high speed (up to 38 Mbps) to all users equipped with an antenna of a diameter as small as 50 cm, requiring them to use only a slow-speed terrestrial modem as a return channel.
However, a further analysis of the available bandwidth and the amount of data to be transmitted shows that unicast applications with one-to-one connections do not scale well when used in a satellite broadcasting environment. For example, if 70 kbps as a minimum transmission speed are considered as “high-speed” Internet and if an overlapping factor of 10 (the overlapping factor corresponds to the data which are accessed or demanded simultaneously by the users) is applied in a subscriber market addressing end consumers, the following figures may be obtained:
   10 subscribers 70 kbps   100 subscribers700 kbps 1,000 subscribers 7 Mbps 10,000 subscribers 70 Mbps or 2 transponders100,000 subscribers 20 transponders1 million subscribers200 transponders.
Even if an overlapping factor of 200 instead of 10 (20 times the previous figures) is assumed, as some Internet providers apply to a population over 500,000 home subscribers, still around 100 transponders are needed to serve only 10 million homes. Hence, a direct application of a satellite broadcasting transmission channel seems to be unsuitable for distributing Internet data to end users.